Choice A is the correct answer. Solve for $t$ when $A(t) = 500$.

1. Equation: $500 = 50e^{0.3t}$.
2. Divide: $10 = e^{0.3t}$.
3. Natural log: $\ln(10) = 0.3t$.
4. Solve: $t = \frac{\ln(10)}{0.3} = \frac{2.303}{0.3} \approx 7.68 \approx 7.7$ hours.

💡 Strategic Tip:$\ln(10) \approx 2.303$ is useful to remember.

Choice B is incorrect because this is too long. Choice C is incorrect because this is too short. Choice D is incorrect because this is way too long.